1. Field of the Invention
The invention relates to a vehicular movement indicator safety system which distinguishes between a driver's intention to turn as indicated by existing turn signal equipment and the actual equipment to an initiation of the turn and signals the actual movement information to other vehicles by automatically activating rapidly increased flashing of the turn signal lamps coincident with the vehicular movement.
2. Description of the Prior Art
There are a number of prior art devices known to those of ordinary skill in the art for signalling the intention of a motor vehicle driver. However, most are not fully automatic and very few address the problem of distinguishing between a driver's intention and the actual committment of the motor vehicle to a movement such as a turn. Of particular interest is British Pat. No. 843,893 which alludes to the problem of a turning car keeping oncoming cars in suspense. In particular it includes the following relevant passage:
"The drivers of vehicles approaching in the opposite direction on the left-hand side of the street, particularly if they move at intervals, cannot determine whether the halted motor vehicle wants to change its direction before them or desires to permit them to pass before it. This uncertainty has in many cases the effect of slowing down the traffic on the left-hand side of the street because it is desired to avoid accidents." PA0 "According to this invention a system of flashing traffic indicators for road vehicles is provided capable of giving two different repeating flashing signals on each side of the vehicle and a control switch or switches are provided to select the desired signal and side of the vehicle on which it appears for the purpose of distinguishing between the intention to turn and that to pull over for the purpose of passing another vehicle or obstruction."
British Pat. No. 843,893 describes in a system in which the left front turn signal has two different modes or conditions of operation. In the first mode the vehicle is positioned to turn, but has not started to turn. Under those conditions the left front signal does not flash, but the rear signal does. In the second mode, the oncoming traffic has cleared and the front turn signal is allowed to flash at the usual rate along with the rear signal. The system is not automatic. Apparently the driver exercises direct control over the flasher operation including the temporary deactivation of the front flasher.
British Pat. No. 967,959 is also of possible relevance in that it discloses a signal system in which the turn signal lamps are adapted to flash at either of two rates to differentiate the intents of a driver to turn or to pull out and to pass. That patent includes the following descriptive passage:
While British Pat. Nos. 843,893 and 967,957 generally address the concept of telegraphing the intentions of a driver to oncoming traffic, they nevertheless do not provide a means for automatically and reliably distinguishing between the intention of the driver and the actual committment of the vehicle to a turn.
U.S. Pat. No. 2,308,097 is of general interest in that it discloses a timer controlled system for terminating turn signal operation. If a vehicle stops during timer operation then the timer is de-activated until the vehicle resumes moving.
Finally, U.S. Pat. No. 3,196,311 is of general interest in that it discusses acceptable ranges of flashing rates.
While some prior art references discuss the general desirability of telegraphing the intentions of a driver to oncoming traffic, insofar as understood, none of those references describe an automatic system that reliably distinguishes between the intention of the driver to turn and the actual committment of the driver to the turn.